1. Field of the Invention
The present invention generally relates to dishwashers with pumps driven by electric motors and more specifically to dishwashers having pumps driven by high voltage DC motors.
2. Description Of The Background
Dishwashers have become a common household appliance. As is well known, implements and utensils used for cooking and eating may be placed inside a special waterproof cabinet so that hot soapy water can be sprayed under high, but controlled, pressure to remove food particles, grease, and other debris from the items placed in the dishwasher. The items then become clean so that they may be reused.
Such dishwashers normally include a pump to provide the water spray with a controlled pressure. The water is recirculated by using a coarse filter system. The pumps are normally driven by an electric motor. Currently, most dishwashers use an induction motor, such as a permanent split capacitor motor, to drive the pump, because this type of motor has a reliable construction.
While this type of induction motor has been commonly used for many years, there remain some disadvantages to such a motor. First, in view of high energy costs, the efficiency of the motor is an important consideration. This is especially true as dishwashers are used more extensively. Another disadvantage of the induction motor is the audible noise created. Consumers prefer that the dishwasher create as little noise as possible, especially when the dishwasher is run at night.